1. Field of the Invention
The present invention relates to a semiconductor exposure apparatus and a method of driving the same.
2. Description of Related Art
A semiconductor manufacturing process includes a photolithography process to form a pattern. The photolithography process includes a light exposure process to irradiate light on a reticle to copy the same pattern as the reticle on photoresist coated on a semiconductor wafer. In the light exposure process, it is very important to remove particles remaining on the reticle.
FIG. 1 is a perspective view illustrating a conventional semiconductor exposure apparatus. The semiconductor exposure apparatus includes a light exposure unit 2 for performing a light exposure process to copy a pattern of the reticle on the photoresist coated on the semiconductor wafer.
The light exposure unit 2 includes a lighting portion 10 having a light source and a reflex mirror, a reticle table 12 in which a reticle having a circuit pattern is placed, and a projection lens (not shown) for focusing light passing through the reticle and irradiating it on the semiconductor wafer.
A reticle loader 20 is arranged at a location facing the light exposure portion 2. The reticle loader 20 includes slots 22 in which a plurality of reticles 24 are inserted and stacked.
A pellicle particle detector 30 is arranged under the reticle loader 20 as shown in FIG. 3. The pellicle particle detector 30 irradiates a laser beam on the top surface or the bottom surface of the reticle 24 through an opened door 32 thereof and detects scattered the laser beam so as to detect particles remaining on a top surface or a bottom surface of the reticle 24.
A robot arm 40 is arranged between the light exposure portion 2 and the reticle loader 20 as shown in FIG. 2. The robot arm 40 transfers the reticle 24 stacked in the reticle loader 20 to the pellicle particle detector 30 while moving up and down or left and right. After detection of particles is finished, the robot arm 40 transfers the reticle in the pellicle particle detector 30 to the reticle table 12 and transfers the reticle 24 on the reticle table 12 to the reticle loader 2.
The robot arm 40 is coupled to a second driving unit 45. The second driving unit 45 is arranged to be guided by a moving rail 44. A pair of first driving units 43a and 43b is coupled to both end portions of the moving rail 44. The first driving units 43a and 43b are arranged to be guided by a pair of stationary rails 42a and 42b spaced apart from each other. That is, the robot arm 40 moves up and down along the stationary rails 42a and 42b by the driving units 43a and 43b and moves left and right along the moving rail 44 by the driving units 45.
When it is determined by the pellicle particle detector 30 that particles do not exist on the reticle 24, the robot arm 40 transfers the reticle 24 in the pellicle particle detector 30 to the light exposure portion 2. The lighting portion 10 of the light exposure portion 2 irradiates light on the reticle 24 on the reticle table 12, and light passing through the reticle 24 is irradiated on the photoresist coated on the semiconductor wafer through the projection lens, whereby the photoresist is exposed to light.
When it is determined that particles exist on the reticle 24, the reticle 24 in the pellicle particle detector 30 is drawn out by the robot arm 40. The reticle 24 is transferred and stacked on the reticle loader 20 by the robot arm 40. The reticles 24 on the reticle loader 20 are transferred to a cleaning room, thereby cleaning the reticle 24 using, for example, an air gun. The cleaned reticle 24 is then stacked on the reticle loader 20 and is loaded into the pellicle particle detector 30 by the robot arm 40. The pellicle particle detector 30 detects whether particles remain on the reticle 24. The reticles 24 having particles are transferred to the reticle table 12 by the robot arm 40.
However, the conventional semiconductor exposure apparatus does not include a cleaning apparatus which can clean the reticle 24 having particles directly after detecting whether particles exist on the reticle 24. Therefore, exposure process time is lengthy because the reticle having particles has to be transferred to the cleaning room.
In addition, the cleaning process is performed such that the entire surface of the reticle is cleaned by the air gun without considering the particle size, the particle location, and so on. Consequently, reticle cleaning cannot be performed efficiently.
To overcome the problems described above, preferred embodiments of the present invention provide a semiconductor exposure apparatus which can perform a cleaning process directly after detecting whether particles exist on a reticle.
It is another object of the present invention to provide a semiconductor exposure apparatus which can remove particles remaining on a reticle efficiently.
The present invention is directed to a semiconductor exposure apparatus, comprising: a light exposure portion irradiating light on a semiconductor wafer through a reticle; a pellicle particle detector detecting a particle existing on a surface of the reticle; a particle cleaner cleaning the reticle when the particle exists on the surface of the reticle; a robot arm moving the reticle to a desired location in response to a control signal generated from a main controller; and the main controller controlling an operation of the semiconductor exposure apparatus.
The reticle cleaner includes nozzles exhausting a filtered gas such as air at a predetermined pressure. The nozzles move to a location to efficiently remove the particle on the reticle according to a detection resulting signal of the pellicle particle detector. The nozzles move up and down or left and right by driving units, the driving units being guided along rails. The nozzles rotate at a predetermined angle by a driving unit, the driving unit being guided along rails. The nozzles have an inclined cross-section.
The nozzles are arranged to remove the particles on both of a top surface and a bottom surface of the reticle.
The semiconductor exposure apparatus further includes a particle removing unit arranged in front of an inlet of the pellicle particle detector to remove the particle on the reticle. The particle removing unit includes a plurality of nozzles, the pluraliy of the nozzles exhausting a filtered gas such as air at a constant pressure to remove the particle on the reticle. The nozzles have a cross-section inclined in a direction opposite to a direction that the reticle is loaded into the pellicle particle detector. The particle removing unit further includes an air filter filtering an air and an air pressure controller controlling a pressure of an air exhausted through the nozzles.
The present invention further provides a method of driving a semiconductor exposure apparatus, comprising: a) loading a reticle into a pellicle particle detector; b) detecting a particle existing on the reticle by the pelliticle particle detector; c) moving the reticle to a cleaning location when the reticle exists on the reticle; d) moving a reticle cleaner to the reticle; and e) cleaning the reticle by the reticle cleaner.
The method further includes removing the particle on the reticle directly before the reticle is loaded into the pellicle particle detector.